2005 Salt Lake City Annual Meeting (October 16–19, 2005)

Paper No. 29
Presentation Time: 1:30 PM-5:30 PM


ABDUL, Nicole and SAUTTER, Leslie, Geology and Environmental Geosciences, College Of Charleston, 66 George St, Charleston, SC 29424, naabdul@edisto.cofc.edu

Benthic foraminifera are morphologically diverse protists found in habitats ranging from the shallow inter-tidal zones of marshes and bays to the depths of the open oceans. Although globally distributed, foraminifera are environmentally specific and therefore knowledge of their modern day distribution can provide scientists with valuable insight into reconstructing paleo-bathymetry, paleo-stratigraphy, and ultimately paleo-climates. In excess of seven hundred (700) studies have been conducted on the distribution of benthic foraminifera around North America; however, very few address their distribution along the eastern North American continental shelf. In this study, eight (8) sediment grab samples, collected along the Charleston Transect of South Carolina's continental shelf, in waters eleven (11) to ninety-six (96) meters deep were analyzed for benthic foraminifera distribution. A total of twenty-five (25) genera were identified, with 6 being classified as “dominant” or constituting more than 5 percent of the forams identified at any given station. These six (6) genera in order of decreasing dominance were Quinqueloculina, Textularia, Hanzawaia, Cibicides, Triloculina and Elphidium. Moving from the inner to outer continental shelf, a shift in the dominance, distribution and diversity of genera was observed and distinct “generic predominance facies” became apparent. Additionally, genera were grouped based on the texture of their test/ exoskeleton into three categories - Milliolid (Porcelain tests Quinquloculina, Triloculina, Spirolculina, Pyrgo), Agglutiate (Textured tests Textularia, Bigenerina and Rotalaria (Hyaline tests all forams not in the aforementioned groups). Three assemblages emerged with the Miliolids dominating the inner shelf, Miliolid, Rotalaria and Agglutinate transitioning in the mid shelf region and Rotalaria dominating the outer shelf. Although this pattern of distribution along the Charleston transect compliments previously established and documented patterns along the Southern coast of Florida and into the Gulf of Mexico, further studies are required to conclusively map the distribution of benthic foraminiferal assemblages along North America's eastern continental shelf.